They come in all shapes and sizes now (most often a metallic version the size of a cigarette lighter), but Pico's USB flash drive is purported to be the smallest on the market. It's a tad bigger than a postage stamp and weighs less than a nickel, so we believe them. Water, shock and freeze resistant, it might be the toughest too. And though the exterior size has been downsized, the space on the inside is vast—8 gigabytes, which if you'll recall is the space equivalent of your entry-level iPod. $40, at ThinkGeek.com.

What's smaller than this flash drive? No flash drive. Drop.io, an online file sharing and storing site, gives you 100 MB of space for free and allows you to upload via e-mail or phone.